A Simple Method for Control Rod Worth Evaluation with Diffusion Codes

Abstract

To present a simple method for calculating the worth of control rods in multiregion reactor cores, the well model approximation is applied to the finite difference diffusion code. The results of calculation are compared with experimental results obtained on the Ozenji Critical Facility, and also with calculations using transport equivalent constants. With its simplicity, the method proposed is accurate enough to suffice amply for most cases where only the reactivity is the end result sought, although the application of this method is limited to control rods inserted in the core region, and gives no information about the detailed neutron flux distribution around the control rod.